TWI766118B - Video decoding apparatus and video decoding method - Google Patents

Abstract

A video decoding apparatus, a computing system including the same, and a video decoding method. The video decoding apparatus may include an entropy decoder and a video decoder. The entropy decoder may be configured to obtain encoding information of a bitstream of an encoded video from a header of the bitstream, the encoding information of the bitstream including a bit depth of the bitstream, and convert a first quantization parameter of the bitstream into a second quantization parameter when the bit depth of the bitstream is different from a reference bit depth. The video decoder may be configured to decode the bitstream based on the second quantization parameter.

Description

Video decoding device and video decoding method

Exemplary embodiments of the inventive concept relate to a video decoding apparatus, a computing system including the same, and/or a video decoding method.

With the development and dissemination of hardware capable of reproducing and storing high-resolution or high-definition video content, there is an increasing need for video codecs that efficiently encode or decode high-resolution or high-definition video content.

Standards such as H.264 Advanced Video Coding (AVC) and H.265/High Efficiency Video Coding (HEVC) have been established and actively used in video codecs to achieve high compression efficiency and high image quality to encode and decode video with a bit depth of 8 bits for each color channel. Traditionally, however, it may be difficult to encode and decode video with a bit depth of 10 or 12 bits for each color channel.

Exemplary embodiments of the present inventive concept provide a video decoding apparatus and/or method for decoding video content having a bit depth greater than that decodable by the apparatus.

Exemplary embodiments of the present inventive concept also provide a computing system including a video decoding device capable of decoding video content having a bit depth greater than that decodable by the device.

However, exemplary embodiments of the inventive concept are not limited to those described herein. The above and other aspects of the exemplary embodiments of the inventive concepts will become more apparent to those having ordinary skill in the art to which exemplary embodiments of the inventive concepts pertain by referencing the detailed description given hereinafter.

According to an exemplary embodiment of the inventive concept, a video decoding apparatus is provided. The video decoding device may include an entropy decoder configured to obtain encoding information of a bitstream of encoded video from a header of the bitstream, the encoding information of the bitstream including the bit depth of the bit stream, and when the bit depth of the bit stream is different from a reference bit depth, converting the first quantization parameter of the bit stream to a second quantization parameters; and a video decoder configured to decode the bitstream based on the second quantization parameter.

According to another exemplary embodiment of the inventive concept, a video decoding apparatus is provided. The video decoding device may include an entropy decoder configured to obtain encoding information of a bitstream of encoded video from a header of the bitstream, the encoding information including an a bit depth, and when the bit depth of the bit stream is greater than a reference bit depth, converting the first quantization parameter of the bit stream into a second quantization parameter; an adder configured to Spatial domain data is generated based on residual data using quantization step sizes and data obtained from intra-predicted or inter-predicted data from the bitstream It is recovered that, when the bit depth of the bit stream is greater than the reference bit depth, the quantization step size corresponds to the second quantization parameter; and a sample adaptive offset (sample adaptive offset) , SAO) filter configured to generate a video output by performing sample adaptive offset filtering on the data in the spatial domain based on the second quantization parameter and a decoding offset.

According to another exemplary embodiment of the inventive concept, a video decoding method is provided. The video decoding method may include: receiving a bitstream of encoded video; obtaining a bit depth of the bitstream from encoding information included in a header of the bitstream; encoding the bit depth and reference bit depth of the bitstream of video, converting a first quantization parameter of the bitstream into a second quantization parameter; and converting the bitstream based on the second quantization parameter The bitstream of encoded video is decoded.

According to another exemplary embodiment of the inventive concept, a computing system is provided. The computing system may include: a memory configured to buffer video output; and a processor configured as a codec to obtain the bitstring from a header of a bitstream of encoded video data encoding information of the stream, the encoding information includes the bit depth of the bit stream, when the bit depth of the bit stream is greater than the reference bit depth, the first bit depth of the bit stream is A quantization parameter is converted into a second quantization parameter to generate spatial domain data based on residual data using quantization steps and data obtained from intra-frame prediction or inter-frame prediction from the bitstream It is recovered that when the bit depth of the bit stream is greater than the reference bit depth, the quantization step size corresponds to the second quantization parameter, by decoding and decoding based on the second quantization parameter Offset performs sample adaptive offset filtering on the data in the spatial domain to generate a video output, and stores the video output in the memory.

As used herein, the term 'unit' or 'module' means, but is not limited to, a software component or a hardware component that performs certain tasks, such as a Field Programmable Gate Array (FPGA) or an application-specific integrated circuit Circuit (Application Specific Integrated Circuit, ASIC). A unit or module may advantageously be configured to reside in an addressable non-transitory storage medium and configured to execute on one or more processors. Thus, for example, a unit or module may include components (eg, software components, object-oriented software components, class components, and task components), procedures, functions, properties, procedures, subroutines, code segments , drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays and variables. The functionality provided for use in the components and units or modules may be combined into fewer components and units or modules, or may be further divided into additional components and units or modules.

The steps of a method or algorithm described in connection with aspects disclosed herein may be implemented directly in hardware, in a software module executed by a processor, or in a combination of hardware and software modules. Software modules can reside in Random Access Memory (RAM), flash memory, Read Only Memory (ROM), Electrically Programmable ROM (EPROM), electrical Electrically Erasable Programmable ROM (EEPROM), scratchpad, hard disk, removable disk, compact disk (CD)-ROM, or non-transitory storage media known in the art in any other form. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. Alternatively, the storage medium may be integrated with the processor. The processor and storage medium may reside in an application specific integrated circuit (ASIC). The ASIC may reside in the user terminal.

FIG. 1 is a block diagram of a video decoding apparatus according to an exemplary embodiment.

Referring to FIG. 1 , a video decoding apparatus according to an exemplary embodiment may include an entropy decoder 100 and a video decoder 200 .

Entropy decoder 100 may receive a bitstream of encoded video data. The bitstream of encoded video data may include, for example, a header that includes attribute information for the encoded video data and a data portion that includes content information for the encoded video data.

Here, the video data received by the entropy decoder 100 may be video data encoded by the H.264 Advanced Video Coding (AVC) protocol or the H.265 High Efficiency Video Coding (HEVC) protocol. However, the exemplary embodiment is not limited to this case, and the video data received by the entropy decoder 100 may also be processed by other video compression standards such as H.261 or H.263, or by formats such as WebM or VP9. Encoded video data.

Additionally, the video data received by the entropy decoder 100 may be video data having, for example, bits with a bit depth of a first size. The bits of the first size may include, for example, 8 bits, 10 bits, 12 bits, or 16 bits. If the video data received by the entropy decoder 100 is video data having a bit depth of 8 bits for each RGB color channel, the video data may have a total bit depth of 24 bits. The video data is not limited to RGB format, but can also be video data including color-difference signals such as YCbCr or YUV.

Entropy decoder 100 may entropy decode the bitstream of encoded video data and parse headers included in the bitstream of encoded video data. Entropy decoder 100 may extract attribute information (eg, the bit depth of the encoded video data) from the parsed header, and then process or provide the extracted attribute information to video decoder 200 . The operation of the entropy decoder 100 will be explained in more detail later with reference to FIG. 3 .

Video decoder 200 may decode the received bitstream of encoded video data based on the attribute information received from entropy decoder 100 . The video decoder 200 can decode video data encoded by, for example, the above-mentioned video compression standards. In some exemplary embodiments, video decoder 200 may decode video data corresponding to multiple video compression standards. That is, the video decoder 200 may include, for example, a plurality of functional blocks capable of decoding different video compression standards. For example, a video decoder may include both functional blocks that can decode video data encoded by H.264 AVC and functional blocks that can decode video data encoded by H.265 HEVC.

The video decoder 200 may include an inverse quantization unit 205, an inverse transform unit 210, an adder 215, a motion compensation unit 220, an intra-frame prediction unit 225, a mode selection unit 230, a deblocking filter 235, sample adaptation Sexual Offset (SAO) filter 240 and image buffer 245. A detailed description of each unit will be given later.

The bit depth of the video data that can be decoded by the video decoder 200 may be different from the bit depth of the encoded video data received by the entropy decoder 100 . That is, the encoded video data received by the entropy decoder 100 may be video data having a bit depth of a first size, and the video data decoded by the video decoder 200 may be video data having a bit depth of a second size size of video data in bits.

When the video decoder 200 decodes the video data having the bits whose bit depth is the second size, it means that the operators included in the video decoder 200 can perform operations on the data whose bit size is the second size, and /or data paths or registers included in the video decoder 200 may process video data having bits with a bit depth of the second size. Bits of the second size may include, for example, 8 bits, 10 bits, 12 bits, or 16 bits.

In some exemplary embodiments, the first size may be larger than the second size. The following explanation will be made based on the assumption that the bits of the first size are larger than the bits of the second size. For example, this may be such that entropy decoder 100 receives a bitstream with video data with a bit depth of 10 bits and video decoder 200 is able to decode video data with a maximum bit depth of 8 bits situation. Conventionally, when the bit depth of the first size is greater than the bit depth of the second size, a video decoder capable of decoding the bit depth of the second size may not be able to decode the received video with the bit depth of the first size. Data decoding.

However, the video decoding device according to the exemplary embodiment can normally decode the encoded video data having the bit depth of the first size by converting, for example, quantization coefficients of the encoded video data, without requiring internal hardware The structure has changed a lot. The bit depth of the second size that can be decoded by the video decoder 200 is hereinafter referred to as the reference bit depth BDO. Information about the reference bit depth BDO may be stored in memory as profile information for the video decoder 200 .

FIG. 2 is a flowchart illustrating a video decoding method according to an embodiment.

Referring to FIG. 2, a video decoding apparatus may perform a video decoding method.

In operation S100, the entropy decoder 100 receives a bitstream of encoded video.

In operation S110, the entropy decoder 100 may obtain the bit depth of the video data included in the header of the bitstream of the encoded video.

In operation S120, the entropy decoder 100 may compare the bit depth BDI of the bitstream of the encoded video with the reference bit depth BDO, and in operation S130, the entropy decoder 100 may determine the bit depth of the encoded video Whether the bit depth BDI of the stream is equal to the reference bit depth BDO.

In operation S140, the entropy decoder 100 may convert the first quantization parameter of the bitstream of the encoded video into the second quantization parameter, and when the bit depth BDI of the bitstream of the encoded video is different from the reference bit In the case of meta-depth BDO, in operation S150, the entropy decoder 100 may decode the bitstream of the encoded video data based on the second quantization parameter of the bitstream of the encoded video data. Alternatively, when the bit depth BDI of the encoded video stream is equal to the reference bit depth BDO, in operation S160, the entropy decoder 100 may decode the encoded bit stream based on the first quantization parameter.

The operation of the entropy decoder 100 will now be explained in more detail with reference to FIG. 3 .

FIG. 3 is a block diagram of the entropy decoder 100 included in the video decoding apparatus shown in FIG. 1 .

Referring to FIG. 3 , the entropy decoder 100 includes a parsing unit 110 and a parameter converting unit 120 . Although not shown in FIG. 3, the entropy decoder 100 may further include a block for entropy decoding the bitstream of encoded video data.

Parsing unit 110 may parse a header included in a bitstream of the encoded video to obtain a bit depth BDI, a first quantization parameter QPI, a first transform coefficient Iij, and a Information of the first offset SAO_OFFSETI for SAO filtering.

In some embodiments, obtaining offset information for SAO filtering may be omitted if video decoder 200 does not decode video data encoded by the H.265 HEVC standard.

Among the information obtained by parsing by the parsing unit 110, the bit depth BDI of the encoded video stream indicates that the encoded video stream has a bit depth of a first size.

The first quantization parameter QPI may have a corresponding first quantization step size QSI. The first quantization parameter QPI indicates that the encoded video stream has been encoded by a first quantization step size QSI corresponding to the first quantization parameter QPI, and the bit string of the encoded video may be coded by using the first quantization step size QSI The stream is inverse quantized to decode the video data.

The correspondence between the first quantization parameter QPI and the first quantization step size QSI will now be explained in more detail with reference to FIG. 4 .

4 illustrates quantization parameters and quantization step sizes used in a video decoding method according to an embodiment.

Referring to FIG. 4 , the correspondence between the first quantization parameter QPI and the first quantization step size QSI is recorded in a table. The table may be, for example, a lookup table (LUT).

In the table shown in FIG. 4, the first quantization parameter QPI is recorded in the left column. For example, the first quantization parameter QPI may have a range of 0-63 when the bitstream of the encoded video data has a bit depth of 10 bits.

The first quantization step size QSI is recorded in the right column of the table. Specifically, when the first quantization parameter QPI is zero, the first quantization step size QSI is QSI0. In addition, when the first quantization parameter QPI is 63, the first quantization step size QSI is QSI63.

For example, the following approximate relationship can be established between the first quantization parameter QPI and the first quantization step size QSI: QSI=2QPI/6 (1).

That is, as shown in FIG. 4 , for example, a 4-fold difference can be established between the first quantization step size QSI10 and the first quantization step size QSI22 corresponding to the first quantization parameter 10 and the first quantization parameter 22 with a difference of 12. ratio. This relationship can be used to convert the first quantization parameter QPI into the second quantization parameter QPO, which will be explained later.

Referring back to FIG. 3 , the first transform parameters Iij are quantized transform coefficients and can be recovered by inverse quantization unit 205 and inverse transform unit 210 to residual data.

For example, when the video decoding method according to an exemplary embodiment is performed on a block having a size of 4×4 pixels, 16 first transform coefficients Iij may be included in one macroblock.

SAO filtering may be performed by SAO filter 240 on the video data that has passed deblocking filter 235 using the first offset SAO_OFFSETI for SAO filtering.

The parsing unit 110 provides the bit depth BDI of the encoded video stream, the first quantization parameter QPI, the first transform coefficients Iij, and the first offset SAO_OFFSETI for SAO filtering to the parameter conversion unit 120 .

The parameter conversion unit 120 compares the bit depth BDI of the encoded video stream with the reference bit depth BDO, and determines whether the bit depth BDI of the encoded video stream is equal to the reference bit depth BDO (operation S120 and operation S130 ) . When the bit depth BDI of the encoded video stream is not equal to the reference bit depth BDO, the parameter conversion unit 120 respectively converts the first quantization parameter QPI of the encoded video stream and the first offset used for SAO filtering The shift SAO_OFFSETI is converted into a second quantization parameter QPO and a second offset SAO_OFFSETO for SAO filtering (operation S140).

The parameter conversion unit 120 can determine whether the bit depth BDI of the encoded video stream received from the parsing unit 110 is equal to the reference bit depth BDO stored in the memory as the profile information of the video decoder 200 .

FIG. 5 is a diagram for explaining quantization parameter conversion performed by a video decoding apparatus according to an embodiment.

In FIG. 5, a table for explaining the conversion of the first quantization parameter QPI into the second quantization parameter QPO by the parameter conversion unit 120 is shown.

The table on the left side of FIG. 5 is identical to the table of FIG. 4 showing the relationship between the first quantization parameter QPI and the first quantization step size QSI in the case where the encoded video stream has a bit depth of 10 bits. That is, the first quantization parameter QPI has a range of 0 to 63, and the first quantization step size QSI corresponding to the first quantization parameter QPI is also divided into 64 steps.

The table on the right side of FIG. 5 is a table showing the relationship between the second quantization parameter QPO and the second quantization step size QSO corresponding to the reference bit depth BDO. If the size of the reference bit depth BDO is 8 bits, the second quantization parameter QPO may have a range of 0-51. Therefore, the second quantization step size QSO may be divided into 52 steps to correspond to the second quantization parameter QPO.

The first quantization step size QSI and the second quantization step size QSO corresponding to quantization parameters of the same value may be equal to each other. That is, the first quantization step size QSI10 and the second quantization step size QSO10 corresponding to the first quantization parameter QPI of 10 and the second quantization parameter QPO of 10, respectively, may be equal to each other.

The parameter conversion unit 120 may convert the first quantization parameter QPI into the second quantization parameter QPO according to the following equation. QPO = QPI + 6 × (BDO-BDI) (QPI + 6 × (BDO - BDI) ≥ 0) = QPI(QPI + 6 × (BDO - BDI) < 0) (2)

For example, when the bit depth BDI and the first quantization parameter QPI of the bitstream of encoded video data are 10 and 22, respectively, and the reference bit depth BDO is 8 bits, the parameter conversion unit 120 may determine the first The binary quantization parameter QPO is 10.

If the value of (QPI + 6 × (BDO-BDI)) is less than zero, the parameter conversion unit 120 may maintain the second quantization parameter QPO at the same value as the first quantization parameter QPI, so that the value of the second quantization parameter QPO Should remain zero or greater.

When maintaining the value of the second quantization parameter QPO as the value of the first quantization parameter QPI, the first transform coefficients Iij may need to be transformed to decode the encoded video stream. This will be explained in detail later.

In order to correspond to the second quantization parameter QPO, the second quantization step size QSO also has a new value QSO10 converted from QSI22.

FIG. 6 is a diagram for explaining transform coefficient conversion performed by the video decoding apparatus according to an embodiment, and FIG. 7 is a diagram for explaining transform coefficient conversion and offset conversion performed by the video decoding apparatus according to an embodiment.

Referring to FIG. 6 , it is shown that the first transform coefficients Iij are converted into second transform coefficients Oij when decoding a macroblock having a size of, for example, 4×4 pixels. Here, i and j are natural numbers from 1 to 4. The macroblock shown in FIG. 6 with a size of 4×4 pixels is merely an example, and may also have pixel sizes of 8×8, 16×16, etc.

When each pixel has a corresponding first transform coefficient Iij, the bit depth BDI of the encoded video bitstream is not equal to the reference bit depth BDO, and the value of the second quantization parameter QPO in Equation 2 remains equal to the first When a value of the parameter QPI is quantized, the parameter conversion unit 120 may convert the first transform coefficients Iij of each pixel into the second transform coefficients Oij to decode the bitstream of the encoded video. The first transform coefficients Iij of the bitstream of encoded video may be transformed into second transform coefficients Oij using the bit-shift operation shown in FIG. 7 .

More specifically, the first transform coefficient Iij can be shifted by a number of bits corresponding to the difference between the bit depth BDI and the reference bit depth BDO of the bitstream of the encoded video. The transform coefficients Iij are converted into second transform coefficients Oij.

Assuming that the bit-depth BDI of the bitstream of the encoded video is greater than the reference bit-depth BDO in the current embodiment as described above, the bit-depth BDO of the encoded video can be obtained by bit-shifting the first transform coefficient Iij to the left by The second transform coefficient Oij is generated by the number of bits corresponding to the difference between the bit depth BDI of the bit stream and the reference bit depth BDO.

Similarly, the first offset SAO_OFFSETI used for SAO filtering can be shifted by the number of bits corresponding to the difference between the bit depth BDI and the reference bit depth BDO of the bitstream of the encoded video , convert the first offset SAO_OFFSETI for SAO filtering into a second offset SAO_OFFSETO for SAO filtering.

Assuming that the bit-depth BDI of the bitstream of the encoded video is greater than the reference bit-depth BDO in the exemplary embodiment described above, the first offset SAO_OFFSETI used for SAO filtering can be left-shifted by bits A second offset SAO_OFFSETO for SAO filtering is generated by the number of bits corresponding to the difference between the bit depth BDI of the encoded video bitstream and the reference bit depth BDO.

If the video decoder 200 does not decode the video data encoded by the H.265 HEVC standard as described above, the conversion of the first offset SAO_OFFSETI for SAO filtering into the second offset SAO_OFFSETO may be omitted.

The entropy decoder 100 may provide the video decoder 200 with a second quantization parameter QPO, a second transform coefficient Oij and a second offset SAO_OFFSETO for SAO filtering and a bitstream of the encoded video.

Decoding a bitstream of encoded video using the video decoder 200 will now be described with reference again to FIGS. 1 and 3 .

The video decoder 200 decodes the encoded video bitstream using the second quantization parameter QPO of the encoded video bitstream.

Inverse quantization unit 205 may receive the entropy decoded bitstream from entropy decoder 100 and inverse quantize the bitstream using a second quantization parameter QPO. Inverse quantization unit 205 provides inverse quantized video data to inverse transform unit 210 .

The inverse transform unit 210 recovers and outputs residual data by inversely transforming the inversely quantized video data. If the first transform coefficient Iij is converted into the second transform coefficient Oij by the parameter transform unit 120 as described above, the inverse transform unit 210 may use the second transform coefficient Oij to inverse transform the inversely quantized video data.

Since the inverse quantization unit 205 and the inverse transform unit 210 decode the bitstream of the encoded video using the second quantization parameter QPO corresponding to the reference bit depth BDO, the video decoder 200 can convert the bit depth having the first size to the bit depth. decodes the encoded video data. That is, the video decoder 200 need not include a decoding module for encoded video data having a bit depth of the first size. Therefore, the complexity of the circuit configuration of the video decoder 200 can be reduced.

When the size of the bit-depth BDI of the encoded video data is equal to the size of the reference bit-depth BDO, the bit-stream of the encoded video data may be divided based on the first quantization parameter QPI and the first transform coefficients Iij decoding.

The processing of the video data after the residual data is recovered by the inverse quantization unit 205 and the inverse transform unit 210 will now be described with reference to FIG. 8 .

FIG. 8 is a flowchart illustrating a video decoding method according to an exemplary embodiment.

Referring to FIG. 8, a video decoding apparatus may perform a video decoding method according to an exemplary embodiment.

In operation S200, the video decoder 200 may recover residual data from the second transform coefficients Oij using the second quantization parameter QPO of the bitstream of the encoded video.

In operation S210, the video decoder 200 may generate predicted data from the encoded video stream by performing intra-frame prediction or inter-frame prediction.

For example, intra-prediction unit 225 performs intra-prediction on intra-mode coding units on a prediction-unit-by-prediction unit basis. In-frame prediction unit 225 may provide intra-frame predicted blocks to mode selection unit 230. Since the intra-frame prediction unit 225 receives the video data recovered by the adder 215, the intra-frame prediction unit 225 can provide the mode selection unit with blocks that are predicted using the encoded blocks within the same frame.

The motion compensation unit 220 may receive the position information of the block that best matches the current block in the spatial domain among the previous blocks included in the previous frame stored in the image buffer 245, and buffer from the frame The processor reads the block corresponding to the location information. The motion compensation unit 220 may provide the read block to the mode selection unit 230 .

Mode selection unit 230 may receive the intra-frame predicted block from intra-frame prediction unit 225 and the read block from motion compensation unit 220 . Mode selection unit 230 may generate the predicted data by selecting either of the two blocks.

In operation S220, the video decoder 200 may generate data in the spatial domain by adding the residual data to the predicted data.

For example, summer 215 may generate data in the spatial domain by adding residual data received from inverse transform unit 210 to the predicted data received from mode selection unit 230 . The spatial domain data produced by adder 215 may be provided to intra-frame prediction unit 225 and deblocking filter 235.

In operation S230, the video decoder 200 may generate a video output from the spatial domain data using the second quantization parameter QPO and the second offset SAO_OFFSETO for SAO filtering.

For example, deblocking filter 235 may deblock received data in the spatial domain. Deblocking filter 235 may transmit the deblocked data to SAO filter 240.

The SAO filter 240 may perform SAO filtering using the second quantization parameter QPO and the second offset SAO_OFFSETO for SAO filtering.

Since the first quantization parameter QPI and the first offset SAO_OFFSETI for SAO filtering have been converted into the second quantization parameter QPO and the second offset SAO_OFFSETO for SAO filtering by the entropy decoder 100, respectively, the SAO filtering The processor 240 may perform SAO filtering on the spatial domain data formed by decoding the video data with a bit depth of the first size.

In operation S240, the video decoder 200 may store the video output in a buffer.

For example, if video decoder 200 does not decode video data encoded by the H.265 HEVC standard as described above, SAO filter 240 may be omitted, and deblocking filter 235 may directly convert the deblocked video data to the image buffer 245.

Alternatively, if the video decoder 200 decodes video data encoded by the H.265 HEVC standard as described above, the SAO filter 240 may output the SAO filtered video data and store the SAO filtered video data in the like buffer 245.

The video data stored in the image buffer 245 may be read and passed to the motion compensation unit 220 when requested by the motion compensation unit 220 .

FIG. 9 is a diagram for explaining transform coefficient conversion and offset conversion performed by a video decoding apparatus according to an exemplary embodiment, and FIG. 10 is a diagram for explaining transform coefficient conversion performed by a video decoding apparatus according to an exemplary embodiment and a graph of the offset transformation.

9 and 10 , although the case where the bit depth BDI of the input video data is greater than the reference bit depth BDO has been described, it can also be executed in the case where the bit depth BDI of the input video data is smaller than the reference bit depth BDO Transformation of quantization parameters, transform coefficients, and offsets for SAO filtering.

For example, in general, when the bit depth BDI of the input video data is smaller than the reference bit depth BDO, the video decoder 200 can directly decode the bit stream of the input video data.

However, there may be situations in which the video decoder 200 cannot directly decode the input video data because the video decoder 200 supports the range extension (RExt) of HEVC, but the profile of the input video data is a baseline profile or a main profile that does not support RExt. profile.

To solve this problem, the first quantization parameter QPI, the first transform coefficient Iij and the first offset SAO_OFFSETI for SAO filtering of the encoded video data can be converted into the second quantization parameter QPO, the second transform coefficient Oij and the The second offset SAO_OFFSETO for SAO filtering.

9 and 10 illustrate examples of reference bit depth BDOs where the bit depth of encoded video data is 8 bits and less than 10 bits.

The table on the left side of FIG. 9 is the same as the table showing the relationship between the first quantization parameter QPI and the first quantization step size QSI in the case where the encoded video stream has a bit depth of 8 bits. That is, the first quantization parameter QPI has a range of 0 to 51, and the first quantization step size QSI corresponding to the first quantization parameter QPI is also divided into 52 steps.

The table on the right side of FIG. 9 is a table showing the relationship between the second quantization parameter QPO and the second quantization step size QSO corresponding to the reference bit depth BDO. If the size of the reference bit depth BDO is 10 bits, the second quantization parameter QPO may have a range of 0-63. Therefore, the second quantization step size QSO may be divided into 64 steps to correspond to the second quantization parameter QPO.

The parameter conversion unit 120 may convert the first quantization parameter QPI into the second quantization parameter QPO according to Equation 2 above. In order to correspond to the second quantization parameter QPO, the second quantization step size QSO also has a new value QSO22 converted from QSI10.

Assuming that the bit-depth BDI of the bitstream of the encoded video as described in the current embodiment is less than the reference bit-depth BDO, the bit-depth BDI of the encoded video can be obtained by bit-shifting the first transform coefficient Iij to the right by the bit-depth of the encoded video The second transform coefficient Oij is generated by the number of bits corresponding to the difference between the bit depth BDI of the metastream and the reference bit depth BDO.

Similarly, assuming that the bit-depth BDI of the bitstream of the encoded video as described in the current embodiment is less than the reference bit-depth BDO, the first offset SAO_OFFSETI bits used for SAO filtering can be adjusted to the right A second offset SAO_OFFSETO for SAO filtering is generated by shifting by a number of bits corresponding to the difference between the bit-depth BDI of the encoded video bitstream and the reference bit-depth BDO.

11 is a block diagram of a computing system 1000 including a video decoding device, according to an embodiment.

11 , a computing system 1000 may include a processor 1010 , a memory element 1020 , a storage element 1030 , an input/output (I/O) element 1040 , a power supply 1050 and a sensor 900 . Computing system 1000 may further include ports for communicating with video cards, sound cards, memory cards, universal serial bus (USB) components, or other electronic components.

The processor 1010 may perform certain calculations or tasks. The processor 1010 may include a video codec 1011 . The video codec 1011 may include the video decoding device described above with reference to FIGS. 1 to 10 . In addition, the video codec 1011 may further include a video encoding device for encoding video data that can be decoded by the video decoding device. The video encoding device and the video decoding device can be integrated with each other.

According to an exemplary embodiment, the processor 1010 may be a microprocessor or a central processing unit (CPU). Alternatively, the processor 1010 may be a graphics processing unit (GPU) or an image signal processor (ISP).

The processor 1010 can communicate with the memory element 1020, the storage element 1030, the sensor 900 and the I/O element 1040 through the address bus, the control bus and the data bus.

According to some exemplary embodiments, the processor 1010 may also be connected to an expansion bus such as a peripheral component interconnect (PCI) bus.

The memory element 1020 may store data required for the operation of the computing system 1000 . For example, the memory device 1020 can be implemented as dynamic random access memory (DRAM), mobile DRAM, static random access memory (SRAM), phase change random access memory phase change random access memory (PRAM), ferroelectric random access memory (FRAM), resistive random access memory (RRAM) and/or magnetic random access memory body (magnetic random access memory, MRAM). For example, memory element 1020 may include memory space allocated to image buffer 245 described above.

The processor 1010 can control the recovered video data to be stored in the memory space allocated as the image buffer 245 in the memory element 1020 .

Storage element 1030 may include solid state drives, hard disk drives, CD-ROMs, and the like. I/O elements 1040 may include input units such as keyboards, keypads, and mice, and output units such as printers and displays.

The power supply 1050 may apply the operating voltage required for the operation of the computing system 1000 .

The sensor 900 may be a photographic element connected to the processor 1010 by a bus or other communication link that performs communication. The sensor 900 can be integrated with the processor 1010 on a single chip. Alternatively, the sensor 900 and the processor 1010 may be integrated on different chips respectively.

Computing system 1000 may be implemented as various forms of packaging. For example, at least some components of computing system 1000 may be mounted using packages such as: package on package (PoP), ball grid array (BGA), chip scale package , CSP), plastic leaded chip carrier (plastic leaded chip carrier, PLCC), plastic dual in-line package (plastic dual in-line package, PDIP), die in waffle pack (die in waffle pack), die Die in wafer form, chip on board (COB), ceramic dual in-line package (CERDIP), plastic metric quad flat pack, MQFP), thin quad flat pack (TQFP), small outline integrated circuit (SOIC), shrink small outline package (shrink small outline package, SSOP), thin small outline package (thin small outline package, TSOP), system in package (system in package, SIP), multi-chip package (multi-chip package, MCP), wafer-level fabrication package (wafer-level fabricated package, WFP) and wafer level Processed stack package (wafer-level processed stack package, WSP).

Computing system 1000 may be construed as any computing system that performs the video decoding method according to the exemplary embodiment. Examples of computing system 1000 include digital cameras, smart phones, mobile phones, and personal digital assistants (PDAs).

While exemplary embodiments of the inventive concept have been specifically shown and described with reference to some exemplary embodiments of the inventive concept, it will be understood by those of ordinary skill in the art that the invention can be Various changes in form and details may be made therein without departing from the spirit and scope of the exemplary embodiments of the inventive concept. The exemplary embodiments are to be considered in an illustrative sense only and not in a limiting sense.

According to one or more exemplary embodiments, the above-described units and/or elements, such as components of a decoding device including entropy decoder 100 and video decoder 200 and subcomponents of each of the above, may use hardware, hardware Implemented in combination with software or a non-transitory storage medium storing software executable in order to perform its functions. The entropy decoder 100 and the video decoder 200 may be implemented in the same hardware platform or in separate hardware platforms.

The video decoder 200 may include a video codec. Video codecs can be implemented in hardware, software, firmware, digital signal processors (DSPs), microprocessors, processors that execute code to configure the processor as a dedicated processor, application-specific integrated circuits circuits (ASICs), field programmable gate arrays (FPGAs), discrete hardware components, or various combinations thereof.

The hardware may be implemented using processing circuitry such as, but not limited to, one or more processors, one or more central processing units (CPUs), one or more controllers, one or more arithmetic Logic unit (arithmetic logic unit, ALU), one or more digital signal processors (DSP), one or more microcomputers, one or more field programmable gate arrays (FPGA), one or more system chips (System -on-Chip, SoC), one or more programmable logic units (programmable logic units, PLU), one or more microprocessors, one or more application specific integrated circuits (ASIC) or can be defined in any other element that responds to and executes the instruction in a manner.

Software may include computer programs, code, instructions, or some combination thereof, to instruct or configure hardware elements, individually or collectively, to operate as desired. Computer programs and/or code may include programs or computer-readable instructions, software components, software modules, data files, data files, data structure, etc. Examples of code include machine code produced by a compiler and higher level code executed using an interpreter.

For example, when the hardware element is a computer processing element (eg, one or more processors, CPUs, controllers, ALUs, DSPs, microcomputers, microprocessors, etc.), the computer processing elements can be configured to The code performs arithmetic operations, logical operations, and input/output operations to implement the code. Once the code is loaded into the computer processing element, the computer processing element can be programmed to execute the code, thereby transforming the computer processing element into a dedicated computer processing element. In a more specific example, when code is loaded into a processor, the processor is programmed to execute the code and operations corresponding to the code, thereby transforming the processor into a special-purpose processor. In another example, the hardware elements may be integrated circuits (eg, ASICs) customized into dedicated processing circuitry.

Hardware elements, such as computer processing elements, may run an operating system (OS) and one or more software applications running on the operating system. Computer processing elements can also access, store, use, process, and create data in response to executing software. For simplicity, one or more exemplary embodiments may be illustrated as one computer processing element; however, those skilled in the art will understand that a hardware element may include multiple processing elements and types of processing elements. For example, a hardware element may include multiple processors or a processor and controller. Additionally, other processing configurations, such as parallel processors, may exist.

Software and/or data may be implemented permanently or temporarily in any type of storage medium that can provide instructions or data to or be interpreted by hardware elements, including but not limited to any machine, A component, physical or virtual device, or computer storage medium or element. The software can also be distributed over network coupled computer systems so that the software is stored and executed in a distributed fashion. In particular, for example, software and data may be stored by one or more computer-readable recording media including the tangible or non-transitory computer-readable storage media discussed herein.

According to one or more exemplary embodiments, the storage medium may also include one or more storage elements in units and/or elements. The one or more storage elements may be tangible or non-transitory computer-readable storage media capable of storing and recording data, such as random access memory (RAM), read only memory (ROM), permanent mass Storage components (such as disk drives) and/or any other similar data storage mechanism. The one or more storage elements may be configured as one or more operating systems and/or store computer programs, code, instructions, or some combination thereof, for implementing the exemplary embodiments described herein. Computer programs, code, instructions, or some combination thereof, may also be loaded into the one or more storage elements and/or one or more computer processing elements from a separate computer-readable storage medium using a drive mechanism. Such separate computer-readable storage media may include Universal Serial Bus (USB) flash drives, memory sticks, Blu-ray/Digital Versatile Disc (DVD)/CD-ROM Drives, memory cards and/or other similar computer-readable storage media. Computer programs, code, instructions, or some combination thereof, may be loaded into the one or more storage elements and/or the one or more storage elements from a remote data storage element through a network interface rather than through a computer-readable storage medium. a computer processing element. Additionally, computer programs, code, instructions, or some combination thereof may be loaded over a network from a remote computing system configured to transmit and/or distribute the computer program, code, instructions, or some combination thereof, to any in the one or more storage elements and/or the one or more processors. Remote computing systems may transmit and/or distribute computer programs, code, instructions, or some combination thereof, via wired interfaces, air interfaces, and/or any other similar medium.

The one or more hardware elements, storage media, computer programs, code, instructions, or some combination thereof may be specifically designed and constructed for the purposes of the exemplary embodiments, or they may be altered and/or Known elements modified for the purposes of the exemplary embodiments.

100‧‧‧Entropy Decoder 110‧‧‧Analysis Unit 120‧‧‧Parameter Conversion Unit 200‧‧‧Video Decoder 205‧‧‧Inverse Quantization Unit 210‧‧‧Inverse Transform Unit 215‧‧‧Adder 220‧‧ ‧Motion Compensation Unit 225‧‧‧Intra-Frame Prediction Unit 230‧‧‧Mode Selection Unit 235‧‧‧Deblocking Filter 240‧‧‧Sample Adaptive Offset Filter 245‧‧‧Image Buffer 900‧ ‧‧Sensor 1000‧‧‧Computing System 1010‧‧‧Processor 1011‧‧‧Video Codec 1020‧‧‧Memory Component 1030‧‧‧Storage Component 1040‧‧‧Input/Output Component 1050‧‧‧ Power Supply BDI‧‧‧Bit Depth BDO‧‧‧Reference Bit Depth Iij‧‧‧First Transform Coefficient Oij‧‧‧Second Transform Coefficient QPI‧‧‧First Quantization Parameter QPO‧‧‧Second Quantization Parameter QSI, QSI0, QSI1, QSI10, QSI22, QSI50, QSI51, QSI62, QSI63‧‧‧First quantization step QSO, QSO0, QSO1, QSO50, QSO51, QSO62, QSO63‧‧‧Second quantization step S100, S110, S120, S130, S140, S150, S160, S200, S210, S220, S230, S240‧‧‧Operation SAO_OFFSETI‧‧‧First offset SAO_OFFSETO‧‧Second offset

These and/or other aspects will become apparent and more easily understood by reading the following description of the embodiments in conjunction with the accompanying drawings, in which: FIG. 1 is a block diagram of a video decoding apparatus according to an exemplary embodiment. FIG. 2 is a flowchart illustrating a video decoding method according to an exemplary embodiment. FIG. 3 is a block diagram of an entropy decoder included in the video decoding apparatus shown in FIG. 1 . FIG. 4 illustrates quantization parameters and quantization step sizes used in a video decoding method according to an exemplary embodiment. FIG. 5 is a diagram for explaining quantization parameter conversion performed by a video decoding apparatus according to an exemplary embodiment. FIG. 6 is a diagram for explaining transform coefficient conversion performed by a video decoding apparatus according to an exemplary embodiment. FIG. 7 is a diagram for explaining transform coefficient conversion and offset conversion performed by a video decoding apparatus according to an exemplary embodiment. FIG. 8 is a flowchart illustrating a video decoding method according to an exemplary embodiment. FIG. 9 is a diagram for explaining quantization parameter conversion performed by a video decoding apparatus according to an exemplary embodiment. FIG. 10 is a diagram for explaining transform coefficient conversion and offset conversion performed by a video decoding apparatus according to an exemplary embodiment. 11 is a block diagram of a computing system including a video decoding device according to an exemplary embodiment.

100‧‧‧Entropy Decoder

200‧‧‧Video Decoder

205‧‧‧Inverse Quantization Unit

210‧‧‧Inverse Transform Unit

215‧‧‧Adder

220‧‧‧Motion Compensation Unit

225‧‧‧In-frame prediction unit

230‧‧‧Mode selection unit

235‧‧‧Deblocking Filter

240‧‧‧sample adaptive offset filter

245‧‧‧image buffer

Claims (17)

A video decoding apparatus, comprising: an entropy decoder including a processing circuit configured to decode bit-depth data by obtaining encoding information of a bitstream of encoded video from a header of the bitstream , the encoding information of the bitstream includes the bit depth of the bitstream, and when the bit depth of the bitstream is different from a reference bit depth, based on the the relationship between the first quantization parameter of the bitstream and the first quantization step size and the difference between the reference bit depth and the bit depth of the bitstream to quantize the first parameters are converted into second quantization parameters such that the first quantization parameter is the same as the first quantization parameter when the bit depth of the bitstream is 10 bits and the reference bit depth is 8 bits The relationship between step sizes is QS _I =2 ^QPI/6 , where QS _I is the first quantization step size and QP _I is the first quantization parameter, and the second quantization parameter has the same a different value for a quantization parameter; and a video decoder including a processing circuit configured to decode the reference bit depth data by receiving the second quantization parameter and the bitstream, and based at least on The second quantization parameter decodes the bitstream with the bit depth. The video decoding device as described in claim 1, wherein the The video decoder includes an adder including a processing circuit configured to generate spatial domain data based on residual data using the second quantization parameter and in-frame prediction from the bitstream or inter-frame predicted data recovered from second transform coefficients of the bitstream; and a sample adaptive offset (SAO) filter configured to perform a A second offset performs sample adaptive offset filtering on the data in the spatial domain to generate a video output. The video decoding apparatus of claim 2, wherein the entropy decoder is configured, when the bit depth of the bit stream is different from the reference bit depth, by making the first An offset is bit-shifted by the difference between the bit-depth of the bitstream and the reference bit-depth to generate the second offset. The video decoding apparatus of claim 2, wherein the entropy decoder is configured to, when the bit depth of the bit stream is different from the reference bit depth, by making the The first transform coefficients of the bitstream are bit-shifted by the difference between the bit depth of the bitstream and the reference bit depth to generate the second transform coefficients. The video decoding device of claim 4, wherein the video decoder is configured to decode from the first quantization step of the bitstream based on a second quantization step size corresponding to the second quantization parameter. Two transform coefficients restore the residual data. The video decoding apparatus of claim 1, wherein the entropy decoder is configured to convert the first quantization parameter to the second quantization parameter based on: QP _O =QP _I +6× (BD _O -BD _I )(QP _I +6×(BD _O -BD _I )

0)=QP _I (QP _I +6×(BD _O -BD _I )<0), where QP _I and QP _O are the first quantization parameter and the second quantization parameter of the bitstream, respectively , and _BDI and _BDO are the bit depth and the reference bit depth, respectively, of the bitstream. The video decoding apparatus of claim 6, wherein the entropy decoder is configured to convert the first transform coefficients of the bitstream into second transform coefficients such that when (QP _I +6 x When the value of (BD _O -BD _I )) is less than zero, the second quantization parameter is the same as the first quantization parameter. The video decoding device as claimed in claim 4, wherein the entropy decoder is configured to not perform the first decoding operation when the bit depth of the bit stream is less than the reference bit depth The quantization parameters and the first transform coefficients are converted. A video decoding apparatus, comprising: an entropy decoder including a processing circuit configured to decode bit-depth data by obtaining encoding information of a bitstream of encoded video from a header of the bitstream , the encoding information includes the bit depth of the bit stream, and when the bit depth of the bit stream is greater than a reference bit depth, based on the first bit depth of the bit stream the relationship between the quantization parameter and the first quantization step size and the difference between the reference bit depth and the bit depth of the bitstream to convert the first quantization parameter into a second quantization parameter, such that the relationship between the first quantization parameter and the first quantization step size when the bit depth of the bitstream is 10 bits and the reference bit depth is 8 bits is QS _I =2 ^QPI/6 , where QS _I is the first quantization step size and QP _I is the first quantization parameter, the second quantization parameter has a different value from the first quantization parameter; addition a processor including processing circuitry configured to generate spatial domain data based on residual data obtained using a second quantization step size and intra-frame prediction or inter-frame prediction from the bitstream Data recovery obtains that when the bit depth of the bit stream is greater than the reference bit depth, the second quantization step size corresponds to the second quantization parameter; and a sample adaptive offset ( SAO) filter including processing circuitry configured to generate a video output by performing sample adaptive offset filtering on the data in the spatial domain based on the second quantization parameter and a second offset. The video decoding apparatus of claim 9, wherein the entropy decoder is configured to, when the bit depth of the bit stream is greater than the reference bit depth, by making the first The offset is bit-left shifted by the difference between the bit depth of the bitstream and the reference bit depth to generate the second offset. The video decoding apparatus of claim 9, wherein the entropy decoder is configured to convert the first quantization parameter to the second quantization parameter based on: QP _O =QP _I +6× (BD _O -BD _I )(QP _I +6×(BD _O -BD _I )

0)=QP _I (QP _I +6×(BD _O -BD _I )<0), where QP _I and QP _O are the first quantization parameter and the second quantization parameter of the bitstream, respectively , and _BDI and _BDO are the bit depth and the reference bit depth, respectively, of the bitstream. A video decoding method, comprising: receiving a bitstream of encoded video; obtaining a bit depth of the bitstream from encoding information included in a header of the bitstream; The relationship between the first quantization parameter of the stream and the first quantization step size and the difference between the reference bit depth and the bit depth of the bit stream converts the first quantization parameter into a second a quantization parameter such that the difference between the first quantization parameter and the first quantization step size when the bit depth of the bitstream is 10 bits and the reference bit depth is 8 bits The relationship is _QSI =2 ^QPI/6 , where _QSI is the first quantization step size and _QPI is the first quantization parameter, and the second quantization parameter has a different value from the first quantization parameter. value; and decoding the bitstream of the encoded video having the bit depth based on at least the second quantization parameter. The method of claim 12, further comprising: generating spatial domain data based on residual data, the residual data using the second quantization parameter and data obtained from intra-frame prediction or inter-frame prediction from the bitstream are recovered from second transform coefficients of the bitstream; and by utilizing the first A quantization parameter and a second offset perform sample adaptive offset filtering on the data in the spatial domain to generate a video output. The method of claim 13, further comprising: in response to the bit depth of the bit stream being different from the reference bit depth, bit shifting by making a first offset The second offset is generated by the difference between the bit depth of the bitstream and the reference bit depth. The method of claim 13, further comprising: in response to the bit depth of the bit stream being different from the reference bit depth, by making the first Transform coefficients are bit-shifted by the difference between the bit depth of the bitstream and the reference bit depth to generate the second transform coefficients. The method of claim 15, further comprising: restoring the residual data from the second transform coefficients of the bitstream based on a second quantization step size corresponding to the second quantization parameter . The method of claim 12, wherein the converting comprises converting the first quantization parameter to the second quantization parameter based on: QP _O =QP _I +6×(BD _O -BD _I )(QP _I +6×(BD _O -BD _I )

0)=QP _I (QP _I +6×(BD _O -BD _I )<0), where QP _I and QP _O are the first quantization parameter and the second quantization parameter of the bitstream, respectively , and _BDI and _BDO are the bit depth and the reference bit depth, respectively, of the bitstream.

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